U.S. patent application number 13/778790 was filed with the patent office on 2014-01-23 for document, image forming apparatus, cover plate, image reading apparatus, image forming method, and image reading method.
This patent application is currently assigned to FUJI XEROX CO., LTD.. The applicant listed for this patent is FUJI XEROX CO., LTD.. Invention is credited to Ryuji FUJIKI, Osamu GOTO, Takeshi KATO, Kousuke KUBOTA, Tomohiro TANIGAWA.
Application Number | 20140022609 13/778790 |
Document ID | / |
Family ID | 49946332 |
Filed Date | 2014-01-23 |
United States Patent
Application |
20140022609 |
Kind Code |
A1 |
TANIGAWA; Tomohiro ; et
al. |
January 23, 2014 |
DOCUMENT, IMAGE FORMING APPARATUS, COVER PLATE, IMAGE READING
APPARATUS, IMAGE FORMING METHOD, AND IMAGE READING METHOD
Abstract
There is provided a document, wherein a measurement image for
measuring a position of an image relative to a document is formed
on a first surface thereof, a designation image for designating a
document position, at which the document is placed on an image
reading apparatus that reads an image, is formed on a second
surface thereof, and wherein the document is spaced from an end
portion of a reading region of the image reading apparatus by
placing the document in accordance with the designation of the
designation image, and the designation image is formed such that
the measurement image is placed in the reading region of the image
reading apparatus.
Inventors: |
TANIGAWA; Tomohiro;
(Kanagawa, JP) ; KUBOTA; Kousuke; (Kanagawa,
JP) ; GOTO; Osamu; (Kanagawa, JP) ; FUJIKI;
Ryuji; (Kanagawa, JP) ; KATO; Takeshi;
(Kanagawa, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
FUJI XEROX CO., LTD. |
Tokyo |
|
JP |
|
|
Assignee: |
FUJI XEROX CO., LTD.
Tokyo
JP
|
Family ID: |
49946332 |
Appl. No.: |
13/778790 |
Filed: |
February 27, 2013 |
Current U.S.
Class: |
358/488 |
Current CPC
Class: |
H04N 2201/0091 20130101;
H04N 2201/04703 20130101; H04N 1/047 20130101; H04N 2201/0414
20130101; H04N 1/00702 20130101; H04N 2201/04703 20130101; H04N
2201/04717 20130101; H04N 2201/04717 20130101; H04N 1/00816
20130101 |
Class at
Publication: |
358/488 |
International
Class: |
H04N 1/00 20060101
H04N001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 18, 2012 |
JP |
2012-159478 |
Claims
1. A document, wherein a measurement image for measuring a position
of an image relative to a document is formed on a first surface
thereof, a designation image for designating a document position,
at which the document is placed on an image reading apparatus that
reads an image, is formed on a second surface thereof, and wherein
the document is spaced from an end portion of a reading region of
the image reading apparatus by placing the document in accordance
with the designation of the designation image, and the designation
image is formed such that the measurement image is placed in the
reading region of the image reading apparatus.
2. The document according to claim 1, wherein the designation image
is used as an image for designating a document position at which
the document is placed on an image reading apparatus that reads an
image in the reading region surrounded by four sides, and wherein
the designation image is formed to be spaced from end portions of
at least three sides among four sides of the reading region of the
image reading apparatus by placing the document in accordance with
the designation of the designation image.
3. The document according to claim 1, wherein when the image
reading apparatus performs reading in a state where a cover plate
for covering the document is further placed on the document, the
designation image is formed such that the document is spaced from
the end portion by associating the designation image with an image
formed in a background section or an end portion of the background
section.
4. The document according to claim 1, wherein the designation image
is formed such that the document is spaced from the end portion by
associating an alignment image with an image formed in the reading
section or an end portion of the reading region of the image
reading apparatus.
5. A document for measurement of the position of the image relative
to the document for the image reading apparatus according to claim
1, wherein the measurement image for measuring the position is
formed of at least first, second, and third images, wherein when
reading the document so as to measure positions of the images, the
image reading apparatus reads the first surface a plurality of
times so as to read the first and second images at first reading
operation and read the second and third images at the subsequent
reading operations, and wherein by placing the document on the
basis of the alignment image, the document is placed at a position
at which the second image is included in the reading region of the
reading section, and the designation image is formed such that
either the first image or the third image protrudes out of the
reading region.
6. The document for measurement of the position of the image
relative to the document for the image reading apparatus according
to claim 5, wherein an image for distinguishing the reading regions
at the time of performing the reading operations a plurality of
times is formed on the second surface.
7. The document for measurement of the position of the image
relative to the document for the image reading apparatus according
to claim 5, wherein an image representing a sequence of the reading
operations at the time of performing the reading operations a
plurality of times is formed on the second surface.
8. An image forming apparatus comprising: an image forming section
that forms a measurement image, which is for measuring a position
of an image relative to a sheet of paper, and a designation image,
which is for designating a document position of a document to be
placed, respectively on different surfaces of the sheet of paper; a
platen that is for placing a document having an image formed on the
sheet of paper by the image forming section; an image reading
section that reads the image of the document placed on the platen;
a detecting section that detects an end portion of the document;
and a calculation section that calculates the position of the image
relative to the document by using the image, which is read by the
image reading section, and the end portion which is detected by the
detecting section, wherein the measurement image is read by the
image reading section in a state where the document is spaced from
an end portion of a reading region of the platen by placing the
document on the platen in accordance with designation of the
designation image and the measurement image is placed in the
reading region of the image reading section.
9. An image forming apparatus comprising: an image forming section
that forms a measurement image, which is for measuring a position
of an image relative to a sheet of paper, and a designation image,
which is for designating a document position of a document to be
placed on a platen, respectively on different surfaces of the sheet
of paper; a platen that is for placing a document having an image
formed on the sheet of paper by the image forming section; an image
reading section that reads the image of the document, which is
placed on the platen, in a state where the document is spaced from
an end portion of a reading region of the platen by placing the
document on the platen in accordance with designation of the
designation image and the measurement image is placed in the
reading region of the image reading section; and a correction
section that corrects relative positions of the image formed in the
document and an end portion of the document in accordance with a
result of the reading performed by the image reading section.
10. The image forming apparatus according to claim 8, wherein the
image forming section forms a cover sheet which is used to cover
the document, and wherein when reading the document on the platen,
the image reading section performs the reading in a state where the
document is spaced from the end portion by further placing the
cover sheet on the document and associating the designation image
with an image formed on a background section or an end portion of
the background section.
11. The image forming apparatus according to claim 10, wherein when
reading the document in which at least first, second, and third
images are formed as the measurement image so as to measure
positions of the images, the image reading section reads a first
surface a plurality of times so as to read the first and second
images at first reading operation and read the second and third
images at the subsequent reading operations, wherein by placing the
document on the basis of the alignment image, the document is
placed at a position at which the second image is included in the
reading region of the image reading section, and the document is
placed such that either the first image or the third image
protrudes out of the reading region, and wherein the image forming
apparatus further comprises a calculation section that calculates a
distance between the first image and the third image on the basis
of the second image which is read by the image reading section a
plurality of times.
12. A cover plate, wherein on a document on which a designation
image for designating a position of an original document to be
placed on a platen is formed, an indication image for indicating a
position of the document to be placed is formed, and wherein when
the document is read, in a state where the cover plate is placed at
a position designated as the position at which the document is
placed on the platen, the indication image is formed such that the
document is spaced from an end portion of a reading region of the
image reading section by placing the document so as to associate
the designation image with the indication image.
13. An image reading apparatus comprising: a platen that is for
placing a document having an image formed on a sheet of paper by an
image forming section for respectively forming a measurement image,
which is for measuring a position of an image relative to the sheet
of paper, and a designation image, which is for designating a
document position of the document to be placed on the platen, on
different surfaces of the sheet of paper; an image reading section
that reads the image of the document placed on the platen; a
detecting section that detects an end portion of the document; and
a calculation section that calculates the position of the image
relative to the document by using the image, which is read by the
image reading section, and the end portion which is detected by the
detecting section, wherein the measurement image is read by the
image reading section in a state where the document is spaced from
an end portion of a reading region of the platen by placing the
document on the platen in accordance with designation of the
designation image and the measurement image is placed in the
reading region of the image reading section.
14. An image reading apparatus comprising: a platen that is for
placing a document having an image formed on a sheet of paper by an
image forming section for respectively forming a measurement image,
which is for measuring a position of an image relative to the sheet
of paper, and a designation image, which is for designating a
document position of the document to be placed on the platen, on
different surfaces of the sheet of paper; an image reading section
that reads the image of the document, which is placed on the
platen, in a state where the document is spaced from an end portion
of a reading region of the platen by placing the document on the
platen in accordance with designation of the designation image and
the measurement image is placed in the reading region of the image
reading section; and a correction section that corrects relative
positions of the image formed in the document and an end portion of
the document in accordance with a result of the reading performed
by the image reading section.
15. An image forming apparatus comprising: an image forming section
that forms a measurement image, which is for measuring a position
of an image relative to a sheet of paper, and a designation image,
which is for designating a document position of the document to be
placed, respectively on different surfaces of the sheet of paper; a
platen that is for placing a document having an image formed on the
sheet of paper by the image forming section; a detecting section
that detects an end portion of the document; and a calculation
section that calculates the position of the image relative to the
document by using the end portion, which is detected by the
detecting section, and the image which is read by an image reading
section for reading the image of the document placed on the platen,
wherein the measurement image is read by the image reading section
in a state where the document is spaced from an end portion of a
reading region of the platen by placing the document on the platen
in accordance with designation of the designation image and the
measurement image is placed in the reading region of the image
reading section.
16. An image forming apparatus comprising: an image forming section
that forms a measurement image, which is for measuring a position
of an image relative to a sheet of paper, and a designation image,
which is for designating a document position of the document to be
placed, respectively on different surfaces of the sheet of paper; a
platen that is for placing a document having an image formed on the
sheet of paper by the image forming section; and a correction
section that corrects relative positions of the image formed in the
document and an end portion of the document in accordance with a
result of the reading performed by an image reading section for
reading the image of the document, which is placed on the platen,
in a state where the document is spaced from an end portion of a
reading region of the platen by placing the document on the platen
in accordance with designation of the designation image and the
measurement image is placed in the reading region of the image
reading section.
17. An image forming method comprising: forming a measurement
image, which is for measuring a position of an image relative to a
sheet of paper, and a designation image, which is for designating a
document position of a document to be placed on a platen,
respectively on different surfaces of the sheet of paper; placing a
document having an image formed on the sheet of paper; reading the
image of the document placed on the platen; detecting an end
portion of the document; and calculating the position of the image
relative to the document by using the image, which is read, and the
end portion which is detected, wherein the measurement image is
read in a state where the document is spaced from an end portion of
a reading region of the platen by placing the document on the
platen in accordance with designation of the designation image and
the measurement image is placed in the reading region.
18. An image forming method comprising: forming a measurement
image, which is for measuring a position of an image relative to a
sheet of paper, and a designation image, which is for designating a
document position of a document to be placed on a platen,
respectively on different surfaces of the sheet of paper; placing a
document having an image formed on the sheet of paper; reading the
image of the document, which is placed on the platen, in a state
where the document is spaced from an end portion of a reading
region of the platen by placing the document on the platen in
accordance with designation of the designation image and the
measurement image is placed in the reading region; and correcting
relative positions of the image formed in the document and an end
portion of the document in accordance with a result of the
reading.
19. An image reading method comprising: placing a document having
an image formed on a sheet of paper; reading the image of the
document placed on the platen; detecting an end portion of the
document; and calculating the position of the image relative to the
document by using the image, which is read, and the end portion
which is detected, wherein the measurement image is read in a state
where the document is spaced from an end portion of a reading
region of the platen by placing the document on the platen in
accordance with designation of the designation image and the
measurement image is placed in the reading region.
20. An image reading method comprising: placing a document having
an image formed on a sheet of paper; reading the image of the
document, which is placed on the platen, in a state where the
document is spaced from an end portion of a reading region of the
platen by placing the document on the platen in accordance with
designation of the designation image and the measurement image is
placed in the reading region; and correcting relative positions of
the image formed in the document and an end portion of the document
in accordance with a result of the reading.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based on and claims priority under 35
USC 119 from Japanese Patent Application No. 2012-159478 filed Jul.
18, 2012.
BACKGROUND
Technical Field
[0002] The present invention relates to a document, an image
forming apparatus, a cover plate, an image reading apparatus, an
image forming method, and an image reading method.
SUMMARY
[0003] According to an aspect of the invention, there is provided a
document, wherein a measurement image for measuring a position of
an image relative to a document is formed on a first surface
thereof, a designation image for designating a document position,
at which the document is placed on an image reading apparatus that
reads an image, is formed on a second surface thereof, and wherein
the document is spaced from an end portion of a reading region of
the image reading apparatus by placing the document in accordance
with the designation of the designation image, and the designation
image is formed such that the measurement image is placed in the
reading region of the image reading apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] Exemplary embodiments of the present invention will be
described in detail based on the following figures, wherein:
[0005] FIG. 1 is an overall configuration diagram of an image
forming apparatus according to a first exemplary embodiment;
[0006] FIG. 2 is a diagram illustrating a picture which is
displayed on a display screen of FIG. 1;
[0007] FIG. 3 is a diagram illustrating chart images which are
output;
[0008] FIGS. 4A to 4C are diagrams illustrating a situation in
which a large-size sheet of paper having chart images is placed
between a transparent glass and an upper cover of FIG. 1 when the
sheet of paper is read;
[0009] FIG. 5 is a diagram illustrating a situation in which the
reading regions of the upper and lower side parts of the front
surface of FIG. 3 and the reading regions of the upper and lower
side parts of the back surface of FIG. 3 for respective reading
operations are overlapped on the front surface and back surface of
FIG. 3;
[0010] FIG. 6 is a diagram illustrating a situation in which the
sheet of paper is aligned on the transparent glass when the
large-size sheet of paper having the chart images is read in a
second exemplary embodiment;
[0011] FIGS. 7A and 7B are diagrams illustrating a situation in
which the sheet of paper is aligned on the transparent glass when
the large-size sheet of paper having the chart images is read in a
third exemplary embodiment;
[0012] FIGS. 8A and 8B are diagrams illustrating a situation in
which the sheet of paper is aligned on the transparent glass when
the large-size sheet of paper having the chart images is read in a
fourth exemplary embodiment;
[0013] FIG. 9 is a diagram illustrating black images which are
output by an image forming apparatus on the basis of black image
data stored in a chart image memory of the image forming apparatus
according to a fifth exemplary embodiment;
[0014] FIGS. 10A and 10B are diagrams illustrating a situation in
which the sheet of paper is aligned on the transparent glass when
the large-size sheet of paper having the chart images is read in
the fifth exemplary embodiment; and
[0015] FIGS. 11A to 11C are diagrams illustrating a situation in
which the sheet of paper is aligned on the transparent glass when
the large-size sheet of paper having the chart images is read in a
sixth exemplary embodiment.
DETAILED DESCRIPTION
[0016] Hereinafter, exemplary embodiments of the invention will be
described with reference to the accompanying drawings.
First Exemplary Embodiment
[0017] FIG. 1 is an overall configuration diagram of an image
forming apparatus 10 according to a first exemplary embodiment.
[0018] The image forming apparatus according to the exemplary
embodiment is a copier that not only has a simplex output function
but also has a duplex output function.
[0019] The image forming apparatus 10 includes: an image reading
section 200 that reads an image on a sheet of paper so as to
generate image data representing the image; an image forming
section 100 that forms the image, which is read on the basis of the
image data, on a separate sheet of paper; and an operational
section 270 that receives, from a user, various inputs of image
formation information pieces such as designation of the number of
output sheets, selection of the duplex/simplex output, and
designation of a tray which contains the sheet of paper before
image output.
[0020] The operational section 270 is provided with a touch panel
type display screen 2701 and a button group 2702 that includes a
start button for issuing an instruction to start image reading and
image formation, numerical value buttons for inputting numerical
values at the time of designating the number of output sheets and
the like, and buttons for controlling the image forming apparatus.
The button group 2702 also includes a correction amount calculation
mode button 2702a for setting a correction amount calculation mode
in the image forming apparatus 10. The mode is for calculating
various correction amounts such as a correction amount of the image
formation position relative to the sheet of paper at the time of
image formation on the sheet of paper and a correction amount of
the magnification of the image on the sheet of paper. The
correction amount calculation will be described later in
detail.
[0021] The image reading section 200 includes: an upper cover 260
that may be opened by a user; and a transparent glass 250 that is
disposed directly beneath the cover 260. The image reading section
200 further includes components that are for reading an image on
the sheet of paper and are disposed under the transparent glass
250.
[0022] The image reading section 200 has a first carriage 210, a
second carriage 220, a lens section 230, and a CCD line sensor 240
as the components for image reading. The first carriage 210 has a
first mirror 212 and a lamp 211, and is a component that is movable
in the horizontal direction of FIG. 1. The first carriage 210 has a
function of causing the lamp 211 to irradiate the reading target
image with light and receiving the reflected light. The second
carriage 220 has a second mirror 221 and a third mirror 222, and is
a component that is movable in the horizontal direction of the
drawing in a similar manner to the first carriage 210. The second
carriage 220 and the lens section 230 have a function of guiding
the reflected light, which is received by the first carriage 210,
to the CCD line sensor 240. Further, the CCD line sensor 240 has a
function of receiving the reflected light and generating image data
that represents the image.
[0023] Here, the image reading section 200 has a transport reading
mode and a stationary reading mode as reading modes for reading the
image on the sheet of paper. In the transport reading mode, the
sheets of paper 300' placed on a document tray 261 are drawn from a
sheet feeding port 260a one by one, and are transported by a
mechanism, which is not shown in the drawing, to a discharging port
260b through a transport path which is indicated by the chain line
arrow. The transport reading mode is a reading mode in which the
image on the sheet of paper being transported is read by using the
first carriage 210, which is stationary, and the sheet is sent onto
a sheet discharging tray 262. Further, the stationary reading mode
is a reading mode in which the sheet of paper is set to be
stationary on the transparent glass 250 and is read by using the
first carriage 210 which is movable in the direction of the solid
line arrow of the drawing. In the stationary reading mode, a
surface of the transparent glass 250 facing the upper cover 260
side is formed as a sheet tray on which a sheet of paper 300 having
a reading target image is placed. Here, the upper cover 260 is
opened, the sheet of paper 300 having the reading target image is
placed on the transparent glass 250 such that the surface thereof
faces the lower side of FIG. 1, and then the upper cover 260 is
closed, whereby it is possible to hold the sheet of paper 300 from
the top. In the stationary reading mode, in this state, the sheet
of paper 300 on the transparent glass 250 is irradiated while the
first carriage 210 is moved, whereby the image on the sheet of
paper 300 is read. When the first carriage 210 is moved, the second
carriage 220 is also moved at a half of the speed of the first
carriage 210 in the same direction such that the optical path
length is kept constant until the light reflected from the sheet of
paper reaches the CCD line sensor 240.
[0024] The image forming section 100 includes: image forming units
1K, 1C, 1M, and 1Y that form images with respective colors of black
(K), cyan (C), magenta (M), and yellow (Y); and an exposure section
5 that emits laser light. The image forming units 1K, 1C, 1M, and
1Y respectively include electrophotographic laminated-type
developer holding members 11K, 11C, 11M, and 11Y that are rotated
in the respective directions of the arrow Bk, the arrow Bc, the
arrow Bm, and the arrow By of FIG. 1. Here, each image forming unit
is provided with not only the above-mentioned developer holding
member but also a charger and a developer unit which are not shown
in the drawing. The developer holding member in each image forming
unit is charged by the charger not shown in the drawing such that
the electric potential of the surface thereof reaches a
predetermined electric potential, and the exposure section 5
performs raster scanning on the charged developer holding member
with the laser light in a direction along each rotational shaft of
the rotating developer holding members 11K, 11C, 11M, and 11Y.
Thereby, an electrostatic latent image based on electric potential
distribution is formed on the developer holding member. The toner
in the developer, which contains the charged toner, is attached
onto the electrostatic latent image by the developer unit not shown
in the drawing, and the electrostatic latent image is developed.
Thereby, the image developed by the toner is formed on the
developer holding member.
[0025] Further, an intermediate transfer belt 2, which is moved in
the direction of the arrow A of FIG. 1 in contact with the
respective developer holding members, is provided on the lower
sides of the respective image forming units 1 of FIG. 1. The
respective primary transfer rollers 110K, 110C, 110M, and 110Y are
provided at positions at which the rollers face the respective
developer holding members 11K, 11C, 11M, and 11Y with the
intermediate transfer belt 2 interposed therebetween. The
intermediate transfer belt 2 is subjected to transfer (primary
transfer) of the developed images formed on the respective
developer holding members, and carries the primary transfer
images.
[0026] In addition to the image forming units 1K, 1C, 1M, and 1Y,
the intermediate transfer belt 2, and the exposure section 5
mentioned above, the image forming section 100 further includes: a
secondary transfer roller 3a that secondarily transfers the primary
transfer images on the intermediate transfer belt 2 onto the sheet
of paper; and a fixing unit 4 that fixes the unfixed secondary
transfer images, which are transferred onto the sheet of paper,
onto the sheet of paper. Further, a sensor 2a, which detects the
respective color test images formed by the respective image forming
units and transferred onto the intermediate transfer belt 2 at the
time of adjusting the relative positions and magnifications among
the primary transfer images from the respective developer holding
members, is provided in the vicinity of the intermediate transfer
belt 2. In the adjustment of the relative positions and the
magnifications, the sensor 2a detects the respective color test
images, which are transferred onto the intermediate transfer belt
2, and adjusts the image forming units 1K, 1C, 1M, and 1Y such that
the relative positions and magnifications among the respective
color test images are set to appropriate positions and
magnifications on the basis of the detection results.
[0027] Further, the image forming section 100 also includes: three
trays of a first tray 70A, a second tray 70B, and a third tray 70C
that respectively houses the sheets of paper; and a driving roller
30 that drives the intermediate transfer belt 2. The intermediate
transfer belt 2 is circulated in the direction of the arrow A of
FIG. 1 by the driving force which is applied from the driving
roller 30 in a state where the belt is stretched by the driving
roller 30 and other plural rollers. The intermediate transfer belt
2 is tightly pressed by the backup roller 3b toward the secondary
transfer roller 3a. The primary transfer images on the intermediate
transfer belt 2 are secondarily transferred onto the sheet of paper
which is drawn from any one of the first tray 70A, the second tray
70B, and the third tray 70C by the operation of the secondary
transfer roller 3a and is transported to the secondary transfer
roller 3a. The sheet of paper subjected to the secondary transfer
is further transported, the secondary transfer images on the sheet
of paper are fixed onto the sheet of paper by the fixing unit 4,
and the sheet is discharged onto the sheet discharging tray 10.
Here, a cleaning device 2b is provided in the vicinity of the
intermediate transfer belt 2, and the toner, which remains on the
intermediate transfer belt 2 after the secondary transfer onto the
sheet of paper, is removed by the cleaning device 2b. Further, the
above-mentioned respective color test images on the intermediate
transfer belt 2, which are formed at the time of adjusting the
relative positions and magnifications among the primary transfer
images from the respective developer holding members, are not
secondarily transferred by the secondary transfer roller 3a but
removed by the cleaning device 2b.
[0028] The image forming apparatus 10 is provided with a controller
6 that controls the respective sections in the image forming
section 100. The controller 6 includes a readout image memory 64
that stores the image data which is generated by the CCD line
sensor 240 of the above-mentioned image reading section 200.
Further, in the image forming apparatus 10, errors in the
dimensions/positions of the image forming units 1K, 1C, 1M, and 1Y
and transport of the sheet of paper and the like cause deviation in
the image formation position on the sheet of paper and change in
image magnification. Therefore, as described later in detail, in
the image forming apparatus 10, the chart images are formed on a
sheet of paper, and the chart images on the sheet of paper are read
by the image reading section 200, thereby calculating various
correction amounts such as the correction amount of the image
formation position relative to the sheet of paper and the
correction amount of the magnification of the image on the sheet of
paper. Hence, the controller 6 includes not only the
above-mentioned readout image memory 64 but also a chart image
memory 65 that stores the chart image data which represents the
chart images used in calculation of the correction amounts to be
described later. Further, the controller 6 may include a first tray
memory 61, a second tray memory 62, and a third tray memory 63 that
store the calculated correction amounts. The memories correspond to
the first tray 70A, the second tray 70B, and the third tray 70C
mentioned above, respectively. The reason why the memories storing
the correction amounts are provided to correspond to the trays as
described above is that a degree of deviation in the image
formation position on the sheet of paper and a degree of change in
image magnification become different in accordance with the path in
which the sheet of paper is drawn from the tray. Here, each of the
trays 70A, 70B, and 70C is configured such that the size of the
sheet of paper to be contained therein is set in advance. Even when
the power supply is turned on/off, the previous setting is still
valid unless the setting is made again. It should be noted that the
exemplary embodiment of the invention may have a configuration in
which the size is automatically sensed.
[0029] In order to form the image based on the image data stored in
the readout image memory 64 on the sheet of paper, the controller 6
reads the correction amounts from the memory corresponding to the
tray designated by an user's operation through the operational
section 270, performs various correction processes such as a
process of correcting the image formation position and a process of
correcting the image magnification on the image data which is
stored in the readout image memory 64 on the basis of the read
correction amounts, and causes the above-mentioned exposure section
5 to form electrostatic latent images based on the image data
subjected to the correction processes. Here, the correction amounts
are constituted of two-type correction amounts of correction
amounts for the front surface at the time of image formation on the
front surface in the duplex output and correction amounts for the
back surface at the time of image formation on the back surface in
the duplex output. In the image formation performed when the duplex
output is set, the correction process is performed on the image
data, which represents the image on the front surface as a surface
subjected to the first output of the image between the both
surfaces of the sheet of paper, on the basis of the correction
amounts for the front surface, and the correction process is
performed on the image data, which represents the image on the back
surface as a surface subjected to the second output of the image,
on the basis of the correction amounts for the back surface. In
contrast, in the image formation performed when the simplex output
is set, the correction process is performed on the image data, on
the basis of the correction amounts for the front surface.
[0030] Next, a sequence of operations including the image reading
and image formation on the sheet of paper in the image forming
apparatus 10 will be described. Here, the case of employing the
stationary reading mode will be exemplified.
[0031] A user places the sheet of paper between the transparent
glass 250 and the upper cover 260 such that the surface having the
reading target image faces the lower side of FIG. 1. In this state,
the user designates the tray for containing the sheet of paper used
in image formation, selects the duplex/simplex output, designates
the number of output sheets through the operational section 270,
and presses the start button (not shown in the drawing) which
issues an instruction to start image reading and image formation in
the button group 2702. Then, light is emitted from the lamp 211 in
the first carriage 210, and the light emitted by the lamp passes
through the transparent glass 250 and is reflected on the sheet of
paper 300. Subsequently, the reflected light passes the first
mirror 212 of the first carriage 210 and the second mirror 221 and
the third mirror 222 of the second carriage 220, and is imaged on
the CCD line sensor 240 by the lens section 230. In FIG. 1, the
path of the light is indicated by the dotted line arrow in the
image reading section 200. The first carriage 210 is moved in the
direction (sub-scanning direction) of the solid line arrow in the
image reading section 200 while such irradiation of light is
performed by the lamp, and the second carriage 220 is also moved in
the same direction at a half of the movement speed of the first
carriage 210. Thereby, when the entire image on the sheet of paper
300 is irradiated, the light reflected from any portion of the
image is imaged on the CCD line sensor 240 in a state where the
optical path length thereof is kept constant. In such a manner, the
image data based on the reflected light of the entire image is
generated by the CCD line sensor 240. Each generated image data is
subjected to various signal processes such as analog/digital
conversion by a processing circuit not shown in the drawing,
thereafter sent to the controller 6, and stored in the readout
image memory 64 in the controller 6. Whenever a user places the
opposite surface of the sheet of paper 300 or a surface of a new
sheet of paper having a new image on the transparent glass 250 and
presses the start button, such generation of the image data and
storage of the image data in the readout image memory 64 are
repeated.
[0032] The controller 6 reads the correction amounts from the
memory, which corresponds to the designated tray, among the first
tray memory 61, the second tray memory 62, and the third tray
memory 63, and performs various correction processes, such as a
process of correcting the image formation position and a process of
correcting the image magnification, on the image data which is
stored in the readout image memory 64 on the basis of the read
correction amounts. Then, the controller 6 causes the exposure
section 5 to form electrostatic latent images, which are based on
the image data subjected to the correction processes, on the
charged developer holding members 11K, 11C, 11M, and 11Y. Each
formed electrostatic latent image is developed with the toner in
the developer including a color toner corresponding to each image
forming unit by the developer unit in each image forming unit,
thereby forming a developed image with each color. The developed
images with the respective colors, which are formed by the
respective image forming unit in such a manner, are sequentially
transferred (primarily transferred) onto and overlapped on the
intermediate transfer belt 2 at the primary transfer rollers 110K,
110C, 110M, and 110Y corresponding to the respective developer
holding members, thereby forming a multi-color primary transfer
image. Subsequently, the multi-color primary transfer image is
carried to the secondary transfer roller 3a by the intermediate
transfer belt 2. Meanwhile, the sheet of paper in the designated
tray among the first tray 70A, the second tray 70B, and the third
tray 70C is drawn as the multi-color primary transfer image is
formed, and is transported by a pair of first transport rollers 41a
and a pair of second transport rollers 41b, and the posture of the
sheet of paper is further correctly adjusted by a pair of alignment
rollers 40. Further, at the timing when the primary transfer image
on the intermediate transfer belt 2 reaches the position of the
secondary transfer roller 3a, the sheet of paper is delivered by
the pair of alignment rollers 40 so as to reach the position. Then,
the above-mentioned multi-color primary transfer image is
transferred (secondarily transferred) onto the delivered sheet of
paper by the secondary transfer roller 3a. The sheet of paper
subjected to the secondary transfer is further transported by a
transport belt 31, and the fixing process is performed on the
secondary transfer image on the sheet of paper by the fixing unit
4. In FIG. 1, the sheet transport path in this case is indicated by
the dotted line arrow directed to the right in the image forming
section 100. It should be noted that the toner, which remains on
the intermediate transfer belt 2 after the secondary transfer onto
the sheet of paper, is removed by the cleaning device 2b.
[0033] When the simplex output is selected, by passing the sheet of
paper through the sheet transport path just once, the secondary
transfer image is fixed in the fixing unit 4. Thereafter, the sheet
passes the pair of delivery rollers 40a, and is directly discharged
onto the sheet discharging tray 10a.
[0034] In contrast, when the duplex output is selected, by passing
the sheet through the above-mentioned sheet transport path
indicated by the arrow directed to the right, the secondary
transfer image is transferred and fixed onto one surface of the
sheet of paper. Thereafter, the sheet is not transported toward the
pair of delivery rollers 40a but transported to the lower side
through the path, which is indicated by the dotted line arrow
directed to the lower side, through a pair of first duplex
transport rollers 40b. Subsequently, the transport direction of the
sheet of paper is changed to the upward direction by reversing the
rotation direction of a pair of second duplex transport rollers
40c, and the sheet passes a pair of third duplex transport rollers
40d and a pair of fourth duplex transport rollers 40e through the
path indicated by the dotted line arrow directed to the left,
passes the pair of first transport rollers 41a, the pair of second
transport rollers 41b, and the pair of alignment rollers 40, and is
transported again toward the secondary transfer roller 3a. Here,
during the time from when the sheet of paper is subjected to the
transfer by the secondary transfer roller 3a for the first time to
when the sheet reaches the position of the secondary transfer
roller 3a again, a new multi-color primary transfer image is formed
on the intermediate transfer belt 2 in the same manner mentioned
above. Then, when the sheet of paper reaches the secondary transfer
roller 3a for the second time, the new multi-color primary transfer
image is secondarily transferred onto the surface opposite the
surface of the sheet of paper which is subjected to the secondary
transfer for the first time. Subsequently, when a fixing process is
performed on the new secondary transfer image on the opposite
surface by the fixing unit 4, the sheet of paper, of which both
surfaces has the fixed images formed thereon, is discharged onto
the sheet discharging tray 10a. Here, the toner, which remains on
the intermediate transfer belt 2 after the secondary transfer onto
the opposite surface of the sheet of paper, is removed by the
cleaning device 2b.
[0035] The above description is pertaining to the operation of the
image forming apparatus 10. In the image forming apparatus 10, the
image, which is read in the above-mentioned manner, is formed on
the sheet of paper.
[0036] The above description is given of the exemplary case of
employing the stationary reading mode. However, in the case of
employing the transport reading mode, the image reading and image
formation are the same as described above except that the image on
the sheet of paper being transported is read by the first carriage
210 which is stationary.
[0037] In addition, in the above description, by correcting the
image formation position in the sheet of paper, the process of
correcting the image formation position is performed on the image
data. However, in the exemplary embodiment of the invention,
instead of such a correction process for image data, correction of
the image formation position in the sheet of paper may be
performed. For example, regarding correction of the position of the
entire image in the sheet transport direction in the sheet of
paper, the correction may be performed by controlling the pair of
alignment rollers 40 so as to change the timing for delivering the
sheet of paper toward the secondary transfer roller 3a. Further,
regarding correction of the position of the entire image in the
direction perpendicular to the sheet transport direction in the
sheet of paper, the correction may be performed by controlling the
exposure section 5 so as to change the write position of the
electrostatic latent image on each developer holding member in the
direction perpendicular to the sheet transport direction (the
rotation shaft direction of each developer holding member).
[0038] Here, in the image forming apparatus 10, in some cases, an
image may be formed on the sheet of paper of which the size is
larger than the readable size of the image reading section 200.
Generally, the readable range of the image reading section 200
coincides with the area of the transparent glass 250 (that is, the
area of the sheet tray). As described above, even when an image is
output onto the sheet of paper of which the size is larger than the
area of the transparent glass 250 (that is, the area of the sheet
tray), in a similar manner to the case of outputting an image onto
the sheet of paper of which the size is smaller than the area of
the transparent glass 250, it is preferable to precisely output an
image with a predetermined size (magnification) at a predetermined
position in the sheet of paper.
[0039] Hereinafter, a description will be given of calculation of
the correction amounts such as the magnification and the image
position of the image formed on the sheet of paper.
[0040] In the image forming apparatus 10, by using the image
forming unit 1K for black (K), the calculation of the correction
amounts such as the magnification and the image position described
below is performed. In addition, the correction amounts in a case
of using image forming units for the other respective colors of
cyan (C), magenta (M), and yellow (Y) may be obtained from the
calculated correction amounts by using the image forming unit 1K
for black (K) through adjustment of the above-mentioned relative
positions and magnifications among the primary transfer images
which are formed by the respective four-color image forming units
including the image forming unit 1K for black (K).
[0041] In the image forming apparatus 10, by pressing the
correction amount calculation mode button 2702a in the operational
section 270 of FIG. 1, the mode for calculating the correction
amounts is set in the image forming apparatus 10. Here, in the
image forming apparatus 10, the correction amount calculation is
performed for each size of the sheet of paper. Thus, whenever the
correction amount calculation mode button 2702a is pressed, the
correction amount calculation mode is changed to a mode
corresponding to each size of the sheets of paper. In addition, in
the image forming apparatus 10, unless the correction amount
calculation mode button 2702a is pressed, a normal mode for
performing the image reading and image formation in the
above-mentioned way is set. The normal mode is a default mode used
when power is applied to the image forming apparatus 10.
[0042] Here, the image forming apparatus 10 is contrived to be able
to calculate the correction amounts for the magnification of the
image, the formation position of the image, and the like on the
sheet of paper of which the size is larger than the area of the
transparent glass 250 (the area of the sheet tray). Hereinafter,
the contrivance will be described. In the following description,
the sheet of paper, of which the size is larger than the area of
the transparent glass 250, is referred to as a "large-size sheet of
paper". For the sake of simplicity, it is assumed that the area of
the transparent glass 250 is larger than a half of the size of the
large-size sheet of paper, but smaller than that of the large-size
sheet of paper. Further, it is assumed that the large-size sheets
of paper are contained in the first tray 70A of FIG. 1, and the
sheets of paper with sizes smaller than the large size are
contained in the second tray 70B and the third tray 70C. Under the
assumption, a description will be given of a case of calculating
the correction amounts by using the large-size sheets of paper in
the first tray 70A.
[0043] As described above, in the image forming apparatus 10, the
correction amount calculation is performed for each size of the
sheet of paper. Thus, whenever the correction amount calculation
mode button 2702a is pressed, the correction amount calculation
mode is changed to a mode corresponding to each size of the sheets
of paper. Here, in the image forming apparatus 10, by pressing the
correction amount calculation mode button 2702a in the operational
section 270 of FIG. 1 a predetermined number of times, the mode for
calculating the correction amounts for the formation position of
the image on the large-size sheet of paper is set in the image
forming apparatus 10.
[0044] FIG. 2 is a diagram illustrating a picture which is
displayed on the touch panel type display screen 2701 of FIG. 1
when the mode for calculating the correction amounts for the
magnification of the image, the formation position of the image, or
the like on the large-size sheet of paper is set.
[0045] The following fields, which may be selected by a touch of a
user's finger, are displayed on the screen: three tray fields of a
first tray field 2701e, a second tray field 2701f, and a third tray
field 2701g each of which is for designating the sheet of paper,
onto which chart images are output, through designation of the tray
that contains the sheet of paper; a chart image output field 2701a
for issuing an instruction to output the chart images; a reading
start field 2701b for delivering, to the image forming apparatus
10, the effect of the current instruction of a user to cause the
image forming apparatus 10 to read the chart image; a reading
completion field 2701c for delivering, to the image forming
apparatus 10, the effect that the user completes the work to cause
the image forming apparatus 10 to read the chart image; and an ESC
field 2701d for recovering the normal mode from the correction
amount calculation mode. Here, in the mode for calculating the
correction amounts for the large-size sheet of paper, only the tray
field, corresponding to the tray that contains the large-size
sheets of paper, is selectable, and the tray fields, corresponding
to the trays that do not contain the large-size sheets of paper,
are not selectable. In this drawing, the circumferences of the
second tray field 2701f and the third tray field 2701g,
respectively corresponding to the second tray 70B and the third
tray 70C that do not contain the large-size sheets of paper, are
indicated by the dotted lines, and the dotted lines indicate that
the fields are not selectable even when touched by a user's
finger.
[0046] The first tray field 2701e, which corresponds to the first
tray 70A of FIG. 1 that contains the large-size sheets of paper, is
touched by a user's finger in order to calculate the correction
amounts for the large-size sheet of paper, and then the chart image
output field 2701a is touched by the user's finger in order to
output the chart image. By touching the first tray field 2701e with
the user's finger, it is determined to use the correction amounts
stored in the first tray memory 61 of FIG. 1 as correction amounts
used at the time of outputting the chart image. By touching the
chart image output field 2701a with the user's finger, in the image
forming section 100 of FIG. 1, chart image data representing the
chart images is read from the chart image memory 65 of FIG. 1, and
the correction processes for the image formation position, the
image magnification, and the like are performed on the basis of the
correction amounts stored in the first tray memory 61 at this time.
Then, on the basis of the chart image data after the correction
process, the chart images are output onto both surfaces of the
large-size sheet of paper. The image formation at this time is the
same as image formation at the time of selecting the duplex output
as described above.
[0047] FIG. 3 is a diagram illustrating the output chart
images.
[0048] FIG. 3 shows a front surface 501A and a back surface 501B of
the large-size sheet of paper 400 having the chart images. Here,
the back surface 501B is a surface which is shown when the front
surface 501A is rotated by 180 degrees about the lengthwise
direction of the large-size sheet of paper as a rotation axis.
[0049] As shown in FIG. 3, six lines of an upper horizontal line
601, a center horizontal line 602, a lower horizontal line 603, a
left vertical line 604, a center vertical line 605, and a right
vertical line 606 are printed on either one of the front surface
501A and the back surface 501B of the large-size sheet of paper
400. The lines are an image for detecting information of the image
such as the image formation position.
[0050] Further, when the large-size sheet of paper 400 is placed on
the transparent glass 250 of FIG. 1 and is read, alignment images
801A, 802A, 803A, and 804A used for alignment of the sheet of paper
are printed on the front surface 501A and the back surface 501B of
the large-size sheet of paper 400. Roles of these eight alignment
images 801A, 802A, 803A, and 804A will be described later in
detail.
[0051] As described later, in order to read the front surface 501A
and the back surface 501B of the large-size sheet of paper 400, the
upper side part and the lower side part of the front surface 501A
and the upper side part and the lower side part of the back surface
501B are divisionally read. Corresponding to the reading, four
identification images 801, 802, 803, and 804 for respectively
identifying the upper side part of the front surface 501A, the
lower side part of the front surface 501A, the upper side part of
the back surface 501B, and the lower side part of the back surface
501B are printed on the front surface 501A and the back surface
501B of the large-size sheet of paper. Further, the four
identification images 801, 802, 803, and 804 include not only
identification information for such identification but also
information which specifies the tray (the first tray 70A of FIG. 1
in the example of the description) from which the large-size sheet
of paper 400 is drawn.
[0052] The chart images, which are used in the image forming
apparatus 10 according to the first exemplary embodiment, includes:
detection images that are formed of six lines 601, 602, 603, 604,
605, and 606 which are set on each of the front surface 501A and
the back surface 501B as described above; four alignment images
801A, 802A, 803A, and 804A that are set on each of the front
surface 501A and the back surface 501B; and four identification
images of two identification images 801 and 802 on the front
surface 501A and two identification images 803 and 804 on the back
surface 501B.
[0053] Here, in the chart image, the combined image of the
detection image, which is formed of the six lines 601, 602, 603,
604, 605, and 606 on the front surface 501A, and the two
identification images 801 and 802 on the front surface 501A
corresponds to an example of the measurement image for measuring
the position according to the exemplary embodiment of the
invention. In addition, the four alignment images 801A, 802A, 803A,
and 804A on the back surface 501B correspond to the designation
image for designating the position according to the exemplary
embodiment of the invention relative to the example of the
measurement image for measuring the position. Further, in the chart
image, the combined image of the detection image, which is formed
of the six lines 601, 602, 603, 604, 605, and 606 on the back
surface 501B, and the two identification images 803 and 804 on the
back surface 501B corresponds to an example of the separate
measurement image for measuring the position according to the
exemplary embodiment of the invention. In addition, the four
alignment images 801A, 802A, 803A, and 804A on the front surface
501A correspond to the designation image for designating the
position according to the exemplary embodiment of the invention
relative to the example of the separate measurement image for
measuring the position.
[0054] When the chart images are output, then the output chart
image reading is performed. In the reading of the output chart
images, first the reading start field 2701b of FIG. 2 is touched by
a user's finger, and thereby the effect of the current instruction
of a user to cause the image forming apparatus 10 to read the chart
images is delivered to the image forming apparatus 10. Then, the
chart images are read in the order described below.
[0055] FIGS. 4A to 4C are diagrams illustrating a situation in
which the large-size sheet of paper 400 having chart images is
placed between the transparent glass 250 and the upper cover 260 of
FIG. 1 when the sheet of paper is read.
[0056] Here, a description will be given of an exemplary case where
the large-size sheet of paper 400 of FIG. 3 is placed such that the
upper side part of the front surface 501A thereof faces the
transparent glass 250 side and the upper side part of the back
surface 501B thereof faces the upper cover 260 side in order to
read the upper side part of the front surface 501A thereof.
[0057] First, as shown in FIG. 4A, the large-size sheet of paper
400 of FIG. 3 is placed on the transparent glass 250 (that is, a
platen) such that the upper side part of the front surface 501A of
the large-size sheet of paper 400 faces the transparent glass 250
side. In the case of the placement, the two alignment images 803A
and 804A on the lower side of the drawing are aligned with the
lower side edge 250a of the transparent glass 250 such that the
vertex in a direction farther from a center vertical line 605 in
each substantially triangular mark of the two alignment images 803A
and 804A on the lower side of the drawing among the alignment
images 801A, 802A, 803A, and 804A on the back surface 501B is on
the line of the lower side edge 250a of the transparent glass 250
as shown in FIG. 4A. Thereby, the large-size sheet of paper 400 is
aligned with the transparent glass 250 (that is, the platen) in the
vertical direction of the drawing.
[0058] Next, as shown in FIG. 4B, the black sheet of paper 400a, of
which both entire surfaces are solid black, is placed on the upper
side part of the back surface 501B of the large-size sheet of paper
400 on the transparent glass 250. Thereby, the upper side part is
completely covered by the black sheet of paper 400a. The black
sheet of paper 400a is for providing a black background to the
large-size sheet of paper 400 such that the edge portion of the
large-size sheet of paper 400 is clearly recognized through the
reading. That is, the black sheet of paper 400a covers at least a
part of the space between the end portion of the transparent glass
250 and the large-size sheet of paper 400. The black sheet of paper
400a is one type of a background member as an example of the cover
plate.
[0059] Subsequently, as shown in FIG. 4C, the upper cover 260
covers the top of the black sheet of paper 400a and the upper side
part of the back surface 501B of the large-size sheet of paper 400,
and reading is performed by the image reading section 200 of FIG. 1
in this state. The operation of the image reading section 200 at
this time is the same as that in the above description of FIG. 1,
and the readout data, which represents a part of the read chart
images, is stored in the readout image memory 64. However, contrary
to the normal mode, in a situation in which the correction amount
calculation mode is set, image formation based on the readout data
is not performed.
[0060] Next, reading is performed on the lower side part of the
front surface 501A of the large-size sheet of paper 400 in the
above-mentioned order, and reading is further performed on each of
the upper and lower side parts (refer to FIG. 3) of the back
surface 501B. Here, in order to read the lower side part of the
front surface 501A, when the lower side part of the front surface
501A is intended to be placed on the transparent glass 250, the two
alignment images 801A and 802A on the upper side of the back
surface 501B are aligned with the lower side edge 250a of the
transparent glass 250. Likewise, in the reading performed on the
upper side part of the back surface 501B, the two alignment images
803A and 804A on the lower side of the front surface 501A are
aligned with the lower side edge 250a of the transparent glass 250.
In the reading performed on the lower side part of the back surface
501B, the two alignment images 801A and 802A on the upper side of
the front surface 501A are aligned with the lower side edge 250a of
the transparent glass 250. As described above, in either of the
reading operations, by using the alignment images 801A and 802A or
the alignment images 803A and 804A, the large-size sheet of paper
400 is aligned with the transparent glass 250 (that is, the platen)
in the vertical direction of the drawing.
[0061] As described above, the readout data is generated for each
of the upper and lower side parts of the front surface 501A and the
upper and lower side parts of the back surface 501B, and is stored
in the readout image memory 64.
[0062] FIG. 5 is a diagram illustrating a situation in which the
reading regions of the upper and lower side parts of the front
surface 501A of FIG. 3 and the reading regions of the upper and
lower side parts of the back surface 501B of FIG. 3 for respective
reading operations are overlapped on the front surface 501A and the
back surface 501B of FIG. 3.
[0063] In FIG. 5, when the respective upper side parts and the
respective lower side parts of the front surface 501A and the back
surface 501B of the large-size sheet of paper 400 are placed in
accordance with the placing method described in FIGS. 4A to 4C and
are sequentially read, the respective reading regions are shown as
four reading regions of a first reading region 701, a second
reading region 702, a third reading region 703, and a fourth
reading region 704 indicated by the dotted line. Thus, the area of
each reading region corresponds to the area of the transparent
glass 250 (that is, the area of the platen).
[0064] As shown in FIG. 5, the first reading region 701 and the
second reading region 702 on the front surface 501A are overlapped
with each other in a region in the vicinity of the center
horizontal line 602. Thus, each of the readout data, which
represents the upper side part of the front surface 501A of the
first large-size sheet of paper 400 within the first reading region
701, and the readout data, which represents the lower side part
thereof within the second reading region 702, includes the position
information of the center horizontal line 602. This point is the
same in the back surface 501B. Thus, the position information of
the center horizontal line 602 is common between the readout data,
which represents the upper side part thereof within the third
reading region 703, and the readout data which represents the lower
side part thereof within the fourth reading region 704.
[0065] When the respective reading operations of the upper and
lower side parts of the front surface 501A and the upper and lower
side parts of the back surface 501B are completed and the
respective readout data pieces are stored in the readout image
memory 64, the reading completion field 2701c of FIG. 2 is touched
by the user's finger. When the reading completion field 2701c is
touched by the user's finger, the controller 6 of FIG. 1 extracts
position parameters of the detection images, which are respectively
represented by four readout data pieces, from the four (=2.times.2)
readout data pieces which are stored in the readout image memory 64
by then and respectively correspond to the upper and lower side
parts of the front surface 501A and the upper and lower side parts
of the back surface 501B of the large-size sheet of paper 400
having the chart images. For example, the upper side part of the
front surface 501A of FIG. 5 will be described in detail. First, in
the readout image, the edges of the sheet of paper are detected by
finding places in which the black part as a part of the black sheet
of paper 400a of FIG. 4A is changed into the white part
corresponding to the sheet of paper. On the basis of the detection,
a position of a corner of the sheet of paper, which is one
intersection point between the edges, is set as an origin point O
(refer to the front surface 501A of FIG. 5). Next, the upper
horizontal line 601, the center horizontal line 602, the left
vertical line 604, the center vertical line 605, and the right
vertical line 606 are respectively detected, thereby calculating
the respective coordinates of the six intersection points A.sub.1,
A.sub.2, A.sub.3, A.sub.4, A.sub.5, and A.sub.6. The coordinate
values of the six coordinates are position parameters of the
above-mentioned detection image. The same method is applied to each
of the lower side part of the front surface 501A and the upper and
lower side parts of the back surface 501B, thereby extracting the
position parameters formed of the coordinate values of the six
coordinates.
[0066] Next, the controller 6 of FIG. 1 calculates the various
kinds of position information such as a distance between the upper
horizontal line 601 and the lower horizontal line 603, a distance
between the left vertical line 604 and the right vertical line 606,
a distance between the upper side edge and the upper horizontal
line 601, and a distance between the left side edge and the left
vertical line 604, in each chart image (refer to FIG. 5) of the
front surface 501A and the back surface 501B.
[0067] For example, the distance between the upper horizontal line
601 and the lower horizontal line 603 on the front surface 501A is
calculated in the following manner. First, by finding data which
represents an identification image 801 of FIG. 3 specifying the
upper part of the front surface 501A, the readout data of the upper
part of the front surface 501A is specified among the four readout
data pieces. On the basis of the specified readout data of the
upper part of the front surface 501A, the distance from the
coordinates of the intersection point A.sub.2 between the upper
horizontal line 601 and the center vertical line 605 to the
coordinates of the intersection point A.sub.5 between the center
horizontal line 602 and the center vertical line 605 is calculated.
Next, by finding data which represents an identification image 802
of FIG. 3 specifying the lower part of the front surface 501A, the
readout data of the lower part of the front surface 501A is
specified among the four readout data pieces. On the basis of the
specified readout data of the lower part of the front surface 501A,
similarly to the upper part, the distance from the coordinates of
the intersection point between the lower horizontal line 603 and
the center vertical line 605 to the coordinates of the intersection
point between the center horizontal line 602 and the center
vertical line 605 is calculated. Then, the distance between the
upper horizontal line 601 and the lower horizontal line 603 is
calculated as the sum of the distance calculated in the upper part
and the distance calculated in the lower part.
[0068] Further, the distance between the left vertical line 604 and
the right vertical line 606 on the front surface 501A is calculated
in the following manner. On the basis of the readout data of the
upper part of the front surface 501A specified as described above,
first, the distance from the coordinates of the intersection point
A.sub.4 between the center horizontal line 602 and the left
vertical line 604 to the coordinates of the intersection point
A.sub.6 between the center horizontal line 602 and the right
vertical line 606 is calculated. Next, on the basis of the readout
data of the lower part of the front surface 501A specified as
described above, similarly to the upper part, the distance from the
intersection point between the center horizontal line 602 and the
left vertical line 604 to the coordinates of the intersection point
between the center horizontal line 602 and the right vertical line
606 is calculated. Then, the distance between the left vertical
line 604 and the right vertical line 606 on the front surface 501A
is calculated as the average of the distance calculated in the
upper part and the distance calculated in the lower part.
[0069] Further, the distance between the upper side edge and the
upper horizontal line 601 and the distance between the left side
edge and the left vertical line 604 on the front surface 501A are
calculated as coordinate components, which are constituted of a
coordinate component in a direction along the left vertical line
604 and a coordinate component in a direction along the upper
horizontal line 601, belonging to the coordinates of the
intersection point between the upper horizontal line 601 and the
left vertical line 604, on the basis of the readout data of the
upper part of the front surface 501A specified as described
above.
[0070] Here, the distance between the upper horizontal line 601 and
the lower horizontal line 603 determines the magnification of the
chart image in the lengthwise direction of the sheet of paper of
FIG. 5, and the distance between the left vertical line 604 and the
right vertical line 606 determines the magnification of the chart
image in the widthwise direction of the sheet of paper of FIG. 5.
Further, the distance between the upper side edge and the upper
horizontal line 601 and the distance between the left side edge and
the left vertical line 604 determine the position of the chart
image of the large-size sheet of paper. The controller 6 of FIG. 1
calculates the correction amounts of the image formation position
and magnification necessary for appropriate values of two types of
the magnification and the position of the chart image on the
large-size sheet of paper.
[0071] The above-mentioned position information and the correction
amounts of the back surface 501B are calculated in a similar manner
as to the front surface 501A. Finally, the correction amounts for
the front surface of the large-size sheet of paper and the
correction amounts for the back surface thereof are calculated.
[0072] When the correction amounts are calculated, then the
controller 6 of FIG. 1 specifies the tray (the first tray 70A of
FIG. 1 in the example of the description), from which the
large-size sheet of paper is drawn, on the basis of the
identification image data, and causes the memory, which corresponds
to the specified tray, to store the correction amounts (the
correction amounts for the front surface and the correction amounts
for the back surface). Here, when the correction amounts are
stored, new correction amounts, which are calculated through the
above-mentioned process, are rewritten onto the correction amounts
which are originally stored in the memory.
[0073] The above description is given of calculation of the
correction amounts for the image formation position and the like on
the sheet of paper of which the size is larger than the area of the
transparent glass 250 (the area of the sheet tray), in the image
forming apparatus 10 according to the first exemplary
embodiment.
[0074] As described above, in the chart image used in the image
forming apparatus 10 according to the first exemplary embodiment,
when the upper parts of the front surface 501A and the back surface
501B are intended to be placed on the transparent glass 250, the
alignment images 803A and 804A on the lower side of the center
horizontal line 602 of the back surface 501B and the front surface
501A are aligned with the lower side edge 250a of the transparent
glass 250. In addition, when the lower parts of the front surface
501A and the back surface 501B are intended to be placed on the
transparent glass 250, the alignment images 801A and 802A on the
upper side of the center horizontal line 602 of the back surface
501B and the front surface 501A are aligned with the lower side
edge 250a of the transparent glass 250. Thereby, any readout data
reliably contains the position information of the center horizontal
line 602, and the corners of the sheet of paper are separated from
the edges of the transparent glass. As a result, when the
respective upper side parts and the respective lower side parts of
the front surface 501A and the back surface 501B are read, the
image forming apparatus 10 according to the first exemplary
embodiment is unlikely to cause a reading failure, in which the
readout data not containing data of common portions (for example,
the center horizontal line 602) is generated and thus it is
difficult to calculate the correction amounts when a user makes an
error in placing the large-size sheet of paper 400, and a reading
failure in which it is difficult to sense the edge positions of the
sheet of paper when the readout images are analyzed.
[0075] In particular, by using the edge 250a of the transparent
glass 250 as a target, an additional target for alignment is not
necessary, and it becomes easy to align the sheet of paper.
[0076] The above description is given of the first exemplary
embodiment.
[0077] In addition, in the above description, reading is performed
plural times by using the large-size sheet of paper. However, the
exemplary embodiment of the invention is not limited to this, and
may be applied to a configuration in which reading may be performed
once.
[0078] Further, in the above description, the black sheet of paper
is employed as the background member which is an example of the
cover plate. However, the exemplary embodiment of the invention is
not limited to this, and a color sheet of paper, which is not
black, may also be used, and a sheet of paper, which has a specific
shape or on which an image is formed, may also be used.
Furthermore, the background member made of plastic or acryl other
than paper may be used. The cover plate may be appropriately
changed if it is able to detect the edges of the sheet of paper in
the function necessary for the cover plate, that is, the sheet of
paper and the cover plate only have to be separated.
[0079] Further, in a case where one sheet of paper is divided into
plural regions and is divisionally read plural times, in order to
prevent reading moire, it may be also possible to form images for
distinguishing the regions. Examples of the images for
distinguishing the regions include, for example, characters, signs,
and the like. Furthermore, even the same character or sign may be
used as the images for distinguishing the regions by varying the
densities or the number of images. In addition, such images may be
used in combination with the alignment images.
[0080] Moreover, in order to provide a sequence of the respective
reading operations of the plural regions, for example, the images
may be formed as numbers or the like such that the sequence of the
images for distinguishing the regions may be recognized.
[0081] Further, in the above description, the alignment images are
aligned with the edge of the transparent glass 250. However, it is
necessary for the alignment images to be able to position the sheet
of paper such that the detection images (for example, the center
horizontal line 602) as measurement targets are not out of the
reading region and a space may be interposed between the end
portion of the sheet of paper and the boundary of the reading
region. It is more preferable that the alignment images be formed
at the boundary position between images as targets formed on the
background member or the upper cover.
[0082] Further, in the above description, the marks are used as the
alignment images. However, in the exemplary embodiment of the
invention, various identification shapes or identification signs
such as lines other than the marks may be used. In addition, the
alignment images for designating the range such that the sheet of
paper is in the range may be used.
Second Exemplary Embodiment
[0083] Next, an image forming apparatus according to a second
exemplary embodiment will be described.
[0084] The image forming apparatus according to the second
exemplary embodiment is different from the image forming apparatus
10 according to the first exemplary embodiment shown in FIG. 1 in
that chart image data, which is different from the chart image data
stored in the chart image memory 65 of the image forming apparatus
10 according to the first exemplary embodiment, is stored in the
chart image memory. Except the point described above, the
configuration and the operation of the image forming apparatus
according to the second exemplary embodiment are the same as those
of the image forming apparatus 10 according to the first exemplary
embodiment. Here, the chart images, which are represented by the
chart image data, in the second exemplary embodiment is different
from the chart images in the first exemplary embodiment shown in
FIG. 3 only in that the chart images have different alignment
images. Otherwise, the chart images are the same as the chart
images in the first exemplary embodiment shown in FIG. 3. As
described above, the chart images are different from those of the
first exemplary embodiment, but in the image forming apparatus
according to the second exemplary embodiment, the correction
amounts are calculated in the same order as that of the image
forming apparatus according to the first exemplary embodiment. The
following description will be given focusing on the different point
from the first exemplary embodiment, and a repeated description of
the same components as the first exemplary embodiment will be
omitted. Further, in the drawing, the components the same as those
of the first exemplary embodiment are represented by the same
reference numerals and signs.
[0085] FIG. 6 is a diagram illustrating a situation in which a
sheet of paper 402 is aligned on the transparent glass 250 when the
large-size sheet of paper 402 having the chart images is read in
the second exemplary embodiment.
[0086] FIG. 6 shows an exemplary case where the upper side part of
the front surface is placed toward the transparent glass 250 side
in order to read the upper side part of the front surface of the
large-size sheet of paper 402. In this case, as shown in FIG. 6, a
back surface 502B of the large-size sheet of paper 402 is visible
from the outside. In the chart images on the large-size sheet of
paper 402 of FIG. 6, the two alignment images 801A and 802A on the
upper side of the center horizontal line 602 and the two alignment
images 803A and 804A, which are represented by the substantially
triangular marks, on the lower side thereof in the chart images on
the large-size sheet of paper 400 of FIG. 3 are replaced by an
alignment image 801B and an alignment image 802B. Here, the
alignment image 801B is indicated by the single line extending in
the horizontal direction on the upper side of the center horizontal
line 602, and the alignment image 802B is indicated by the single
line extending in the horizontal direction on the lower side of the
center horizontal line 602. That is, although not shown in FIG. 6,
the same alignment images 801B and 802B are printed on the front
surface opposite to the back surface 502B of FIG. 6 together with
the detection images which are formed of the six lines 601, 602,
603, 604, 605, and 606. Further, four identification images the
same as those of FIG. 3 for identifying those with each other are
printed on four parts of the upper and lower side parts of the back
surface 502B and the upper and lower side parts of the front
surface opposite thereto, respectively. In FIG. 6, among the
images, only two identification images 803 and 804 on the back
surface 502B are shown.
[0087] In order to read the upper side part of the front surface of
the large-size sheet of paper 402, the upper side part of the front
surface is placed on the transparent glass 250. In this case, the
alignment image 802B on the lower side of the drawing is aligned
with the lower side edge 250a of the transparent glass 250 such
that the line of the alignment image 802B on the lower side of the
drawing between the alignment images 801B and 802B on the back
surface 502B is on the line of the lower side edge 250a of the
transparent glass 250 as shown in FIG. 6. Thereby, the large-size
sheet of paper 402 is aligned with the transparent glass 250 (that
is, the platen) in the vertical direction of the drawing.
[0088] After the above-mentioned placement, in a similar manner to
FIGS. 4B and 4C, reading is performed in a state where the sheet is
covered by the upper cover 260 or the black sheet of paper 400a
shown in FIG. 4B, and the readout data is generated.
[0089] Next, reading is performed on the lower side part of the
front surface of the large-size sheet of paper 402 in the
above-mentioned order, and reading is further performed on each of
the upper and lower side parts of the back surface 502B. Here, in
the case of reading the lower side part of the front surface, when
the lower side part of the front surface is intended to be placed
on the transparent glass 250, the alignment image 801B on the upper
side of the back surface 502B is aligned with the lower side edge
250a of the transparent glass 250. In the case of reading the upper
and lower side parts of the back surface 502B, in a similar manner
to the back surface 501B, alignment is also performed by using the
two alignment images on the front surface. As described above, in
either of the reading operations, by using the alignment images
801B and 802B, the large-size sheet of paper 402 is aligned with
the transparent glass 250 (that is, the platen) in the vertical
direction of the drawing.
[0090] As described above, the readout data is generated for each
of the upper and lower side parts of the front surface and the
upper and lower side parts of the back surface 502B, and is stored
in the readout image memory 64. The subsequent flow of the
correction amount calculation is the same as that of the first
exemplary embodiment, and thus a repeated description will be
omitted.
[0091] In the second exemplary embodiment, in a similar manner to
the first exemplary embodiment, any readout data reliably contains
the position information of the center horizontal line 602, and the
corners of the sheet of paper are separated from the edges of the
transparent glass. As a result, when the respective upper side
parts and the respective lower side parts of the front surface and
the back surface are read, the image forming apparatus according to
the second exemplary embodiment is unlikely to cause a reading
failure, in which the readout data not containing data of common
portions (for example, the center horizontal line 602) is generated
and thus it is difficult to calculate the correction amounts when a
user makes an error in placing the large-size sheet of paper 402,
and a reading failure in which it is difficult to sense the edge
positions of the sheet of paper when the readout images are
analyzed.
[0092] Further, by using the edge 250a of the transparent glass 250
as a target, an additional target for alignment is not necessary,
and thus it becomes easy to align the sheet of paper.
Third Exemplary Embodiment
[0093] Next, an image forming apparatus according to a third
exemplary embodiment will be described.
[0094] The image forming apparatus according to the third exemplary
embodiment is different from the image forming apparatus 10
according to the first exemplary embodiment shown in FIG. 1 in that
chart image data, which is different from the chart image data
stored in the chart image memory 65 of the image forming apparatus
10 according to the first exemplary embodiment, is stored in the
chart image memory. Except the point described above, the
configuration and the operation of the image forming apparatus
according to the third exemplary embodiment are the same as those
of the image forming apparatus 10 according to the first exemplary
embodiment. Here, the chart images, which are represented by the
chart image data, in the third exemplary embodiment is different
from the chart images in the first exemplary embodiment shown in
FIG. 3 only in that the chart images have different alignment
images. Otherwise, the chart images are the same as the chart
images in the first exemplary embodiment shown in FIG. 3. As
described above, the chart images are different from those of the
first exemplary embodiment, but in the image forming apparatus
according to the third exemplary embodiment, the correction amounts
are calculated in the same order as that of the image forming
apparatus according to the first exemplary embodiment. The
following description will be given focusing on the different point
from the first exemplary embodiment, and a repeated description of
the same components as the first exemplary embodiment will be
omitted. Further, in the drawing, the components the same as those
of the first exemplary embodiment are represented by the same
reference numerals and signs.
[0095] FIGS. 7A and 7B are diagrams illustrating a situation in
which a sheet of paper 403 is aligned on the transparent glass 250
when the large-size sheet of paper 403 having the chart images is
read in the third exemplary embodiment.
[0096] FIGS. 7A and 7B show an exemplary case where the upper side
part of the front surface is placed toward the transparent glass
250 side in order to read the upper side part of the front surface
of the large-size sheet of paper 403.
[0097] In this case, as shown in FIG. 7A, a back surface 503B of
the large-size sheet of paper 403 is visible from the outside. In
the chart images on the large-size sheet of paper 403 of FIG. 7A,
the two alignment images 801A and 802A and the two alignment images
803A and 804A in the chart images on the large-size sheet of paper
400 of FIG. 3 are replaced by two alignment images 801C and 802C
and two alignment images 803C and 804C. Here, the two alignment
images 801A and 802A are respectively provided in the vicinities of
the edges of the sheet of paper 400 on the upper side of the center
horizontal line 602, and the two alignment images 803A and 804A are
respectively provided in the vicinities of the edges of the sheet
of paper 400 on the lower side of the center horizontal line 602,
but the two alignment images 801C and 802C are respectively
provided at positions close to the vertical line 605 on the upper
side of the center horizontal line 602, and the two alignment
images 803C and 804C are respectively provided at positions close
to the vertical line 605 on the lower side of the center horizontal
line 602. That is, although not shown in FIG. 7A, the same
alignment images 801C, 802C, 803C, and 804C are printed on the
front surface opposite to the back surface 503B of FIG. 7A together
with the detection images which are formed of the six lines 601,
602, 603, 604, 605, and 606. Further, four identification images
the same as those of FIG. 3 for identifying those with each other
are printed on four parts of the upper and lower side parts of the
back surface 503B and the upper and lower side parts of the front
surface opposite thereto, respectively. In FIG. 7A, among the
images, only two identification images 803 and 804 on the back
surface 503B are shown.
[0098] Next, as shown in FIG. 7B, a black sheet of paper 403a is
placed on the upper side part of the back surface 503B of the
large-size sheet of paper 403 on the transparent glass 250.
Thereby, the upper side part is completely covered by the black
sheet of paper 403a. Here, similarly to the black sheet of paper
400a shown in FIG. 4B, the black sheet of paper 403a shown in FIG.
7B is for providing a black background to the large-size sheet of
paper 403 such that the edge portion of the large-size sheet of
paper 403 is clearly recognized through the reading. That is, the
black sheet of paper 403a covers at least a part of the space
between the end portion of the transparent glass 250 and the
large-size sheet of paper 403. However, contrary to the black sheet
of paper 400a shown in FIG. 4B, white target images 811C and 812C
having substantially triangular shapes are printed on the black
sheet of paper 403a shown in FIG. 7B in the vicinity of the edge of
the surface opposite to the surface covering the upper side part of
the back surface 503B of the sheet of paper 403, and both entire
surfaces of the black sheet of paper 403a are solid black except
for the target images 811C and 812C which are printed on one
surface thereof. Here, the transparent glass 250 is formed to be
slightly sunken compared with the surface around the transparent
glass 250. Hence, there is a level difference between the edges of
the transparent glass 250 and the periphery thereof. In a case of
reading the chart images in the third exemplary embodiment, it is
possible to bump the black sheet of paper 403a into both of an
upper side edge 250c and a left side edge 250b of the transparent
glass 250 with the level difference, and thereby the black sheet of
paper 403a is aligned with the transparent glass 250. The two
alignment images 803C and 804C on the lower side of the back
surface 503B of FIG. 7A are aligned with the target images 811C and
812C of the black sheet of paper 403a, which is aligned as
described above, as shown in FIG. 7B. Thereby, the large-size sheet
of paper 403 is aligned with the transparent glass 250 (that is,
the platen) in the vertical and horizontal directions of the
drawing.
[0099] After the sheet is placed as described above, in a similar
manner to FIG. 4C, reading is performed in a state where the sheet
is covered by the upper cover 260, and the readout data is
generated.
[0100] Next, reading is performed on the lower side part of the
front surface of the large-size sheet of paper 403 in the
above-mentioned order, and reading is further performed on each of
the upper and lower side parts of the back surface 503B. Here, in
the case of reading the lower side part of the front surface, when
the lower side part of the front surface is intended to be placed
on the transparent glass 250, the alignment images 801C and 802C on
the upper side of the back surface 503B are aligned with the target
images 811C and 812C of the black sheet of paper 403a aligned as
described in FIG. 7B. In the case of reading the upper and lower
side parts of the back surface 503B, in a similar manner to the
back surface 503B, alignment is also performed by using the four
alignment images on the front surface. As described above, in
either of the reading operations, by using the alignment images
801C and 802C on the upper side or the alignment images 803C and
804C on the lower side, the large-size sheet of paper 403 is
aligned with the transparent glass 250 (that is, the platen) in the
vertical and horizontal directions of the drawing.
[0101] As described above, the readout data is generated for each
of the upper and lower side parts of the front surface and the
upper and lower side parts of the back surface 503B, and is stored
in the readout image memory 64. The subsequent flow of the
correction amount calculation is the same as that of the first
exemplary embodiment, and thus a repeated description will be
omitted.
[0102] In the third exemplary embodiment, in a similar manner to
the first exemplary embodiment, any readout data reliably contains
the position information of the center horizontal line 602, and the
corners of the sheet of paper are separated from the edges of the
transparent glass. As a result, when the respective upper side
parts and the respective lower side parts of the front surface and
the back surface are read, the image forming apparatus according to
the third exemplary embodiment is unlikely to cause a reading
failure, in which the readout data not containing data of common
portions (for example, the center horizontal line 602) is generated
and thus it is difficult to calculate the correction amounts when a
user makes an error in placing the large-size sheet of paper 403,
and a reading failure in which it is difficult to sense the edge
positions of the sheet of paper when the readout images are
analyzed.
[0103] Further, only by using the target images 811C and 812C of
the aligned black sheet of paper 403a as targets, the sheet of
paper may be aligned, and thus it becomes easy to align the sheet
of paper.
[0104] In particular, in the third exemplary embodiment, the
large-size sheet of paper 403 is aligned in the horizontal
direction of the drawing. Hence, it is possible to prevent the
large-size sheet of paper 403 from protruding out of the
transparent glass 250 (that is, the platen) in the horizontal
direction of the drawing.
Fourth Exemplary Embodiment
[0105] Next, an image forming apparatus according to a fourth
exemplary embodiment will be described.
[0106] The image forming apparatus according to the fourth
exemplary embodiment is different from the image forming apparatus
10 according to the first exemplary embodiment shown in FIG. 1 in
that chart image data, which is different from the chart image data
stored in the chart image memory 65 of the image forming apparatus
10 according to the first exemplary embodiment, is stored in the
chart image memory. Except the point described above, the
configuration and the operation of the image forming apparatus
according to the fourth exemplary embodiment are the same as those
of the image forming apparatus 10 according to the first exemplary
embodiment. Here, the chart images, which are represented by the
chart image data, in the fourth exemplary embodiment is different
from the chart images in the first exemplary embodiment shown in
FIG. 3 only in that the chart images have different alignment
images. Otherwise, the chart images are the same as the chart
images in the first exemplary embodiment shown in FIG. 3. As
described above, the chart images are different from those of the
first exemplary embodiment, but in the image forming apparatus
according to the fourth exemplary embodiment, the correction
amounts are calculated in the same order as that of the image
forming apparatus according to the first exemplary embodiment. The
following description will be given focusing on the different point
from the first exemplary embodiment, and a repeated description of
the same components as the first exemplary embodiment will be
omitted. Further, in the drawing, the components the same as those
of the first exemplary embodiment are represented by the same
reference numerals and signs.
[0107] FIGS. 8A and 8B are diagrams illustrating a situation in
which a sheet of paper 404 is aligned on the transparent glass 250
when the large-size sheet of paper 404 having the chart images is
read in the fourth exemplary embodiment.
[0108] FIGS. 8A and 8B show an exemplary case where the upper side
part of the front surface is placed toward the transparent glass
250 side in order to read the upper side part of the front surface
of the large-size sheet of paper 404. In this case, as shown in
FIG. 8A, a back surface 504B of the large-size sheet of paper 404
is visible from the outside. In the chart images on the large-size
sheet of paper 404 of FIG. 8A, the two alignment images 801A and
802A on the upper side of the center horizontal line 602 and the
two alignment images 803A and 804A on the lower side thereof, which
are represented by the substantially triangular marks, in the chart
images on the large-size sheet of paper 400 of FIG. 3 are replaced
by alignment images 801D, 802D, 803D, and 804D. Here, the alignment
image 801D, which has a shape like a single line extending in the
horizontal direction, and the alignment image 802D, which has an
arrow-like shape, are provided on the upper side of the center
horizontal line 602. In addition, the alignment image 803D, which
has a shape like a single line extending in the horizontal
direction, and the alignment image 804D, which has an arrow-like
shape, are provided on the lower side of the center horizontal line
602. That is, although not shown in FIGS. 8A and 8B, the same
alignment images 801D, 802D, 803D, and 804D are printed on the
front surface opposite to the back surface 504B of FIGS. 8A and 8B
together with the detection images which are formed of the six
lines 601, 602, 603, 604, 605, and 606. Further, four
identification images the same as those of FIG. 3 for identifying
those with each other are printed on four parts of the upper and
lower side parts of the back surface 504B and the upper and lower
side parts of the front surface opposite thereto, respectively. In
FIG. 8A, among the images, only two identification images 803 and
804 on the back surface 504B are shown.
[0109] In order to read the upper side part of the front surface of
the large-size sheet of paper 404, the upper side part of the front
surface is placed on the transparent glass 250. In this case, the
alignment image 803D on the lower side of the drawing is aligned
with the lower side edge 250a of the transparent glass 250 such
that the line of the alignment image 803D on the lower side of the
drawing between the alignment images 801D and 803D having
substantially linear shapes on the back surface 504B is on the line
of the lower side edge 250a of the transparent glass 250 as shown
in FIG. 8A. Thereby, the large-size sheet of paper 404 is aligned
with the transparent glass 250 (that is, the platen) in the
vertical direction of the drawing.
[0110] Next, as shown in FIG. 8B, a black sheet of paper 404a is
placed on the upper side part of the back surface 504B of the
large-size sheet of paper 404 on the transparent glass 250.
Thereby, the upper side part is completely covered by the black
sheet of paper 404a. Here, similarly to the black sheet of paper
400a shown in FIG. 4B, the black sheet of paper 404a shown in FIG.
8B is for providing a black background to the large-size sheet of
paper 404 such that the edge portion of the large-size sheet of
paper 404 is clearly recognized through the reading. That is, the
black sheet of paper 404a covers at least a part of the space
between the end portion of the transparent glass 250 and the
large-size sheet of paper 404. However, contrary to the black sheet
of paper 400a shown in FIG. 4B, a white target image 811D having an
arrow-like shape is printed on the black sheet of paper 404a shown
in FIG. 8B in the vicinity of the edge of the surface opposite to
the surface covering the upper side part of the back surface 504B
of the sheet of paper 404, and both entire surfaces of the black
sheet of paper 404a are solid black except for the target image
811D which are printed on one surface thereof. Here, the
transparent glass 250 is formed to be slightly sunken compared with
the surface around the transparent glass 250. Hence, there is a
level difference between the edges of the transparent glass 250 and
the periphery thereof. In a case of reading the chart images in the
fourth exemplary embodiment, it is possible to bump the black sheet
of paper 404a into both of the upper side edge 250c and the left
side edge 250b of the transparent glass 250 with the level
difference, and thereby the black sheet of paper 404a is aligned
with the transparent glass 250. The alignment image 804D having an
arrow-like shape on the lower side of the back surface 504B of FIG.
8A is aligned with the target image 811D of the black sheet of
paper 404a, which is aligned as described above, as shown in FIG.
8B. Thereby, the large-size sheet of paper 404 is aligned with the
transparent glass 250 (that is, the platen) in the horizontal
direction of the drawing.
[0111] After the sheet is placed as described above, in a similar
manner to FIG. 4C, reading is performed in a state where the sheet
is covered by the upper cover 260, and the readout data is
generated.
[0112] Next, reading is performed on the lower side part of the
front surface of the large-size sheet of paper 404 in the
above-mentioned order, and the reading is further performed on each
of the upper and lower side parts of the back surface 504B. Here,
in the case of reading the lower side part of the front surface,
when the lower side part of the front surface is intended to be
placed on the transparent glass 250, the alignment images 801D and
802D on the upper side of the back surface 504B are respectively
aligned with the lower side edge 250a of the transparent glass 250
described in FIG. 8A and the target image 811D of the black sheet
of paper 404a aligned as described in FIG. 8B. In the case of
reading the upper and lower side parts of the back surface 504B, in
a similar manner to the back surface 504B, alignment is also
performed by using the four alignment images on the front surface.
As described above, in either of the reading operations, by using
the alignment images 801D and 802D on the upper side or the
alignment images 803D and 804D on the lower side, the large-size
sheet of paper 404 is aligned with the transparent glass 250 (that
is, the platen) in the vertical and horizontal directions of the
drawing.
[0113] As described above, the readout data is generated for each
of the upper and lower side parts of the front surface and the
upper and lower side parts of the back surface 504B, and is stored
in the readout image memory 64. The subsequent flow of the
correction amount calculation is the same as that of the first
exemplary embodiment, and thus a repeated description will be
omitted.
[0114] In the fourth exemplary embodiment, in a similar manner to
the first exemplary embodiment, any readout data reliably contains
the position information of the center horizontal line 602, and the
corners of the sheet of paper are separated from the edges of the
transparent glass. As a result, when the respective upper side
parts and the respective lower side parts of the front surface and
the back surface are read, the image forming apparatus according to
the fourth exemplary embodiment is unlikely to cause a reading
failure, in which the readout data not containing data of common
portions (for example, the center horizontal line 602) is generated
and thus it is difficult to calculate the correction amounts when a
user makes an error in placing the large-size sheet of paper 404,
and a reading failure in which it is difficult to sense the edge
positions of the sheet of paper when the readout images are
analyzed.
[0115] Further, just by using the lower side edge 250a of the
transparent glass 250 and the target image 811D of the aligned
black sheet of paper 404a as targets, the sheet of paper may be
aligned, and thus it becomes easy to align the sheet of paper.
[0116] In particular, in the fourth exemplary embodiment, the
large-size sheet of paper 404 is aligned in the horizontal
direction of the drawing. Hence, it is possible to prevent the
large-size sheet of paper 404 from protruding out of the
transparent glass 250 (that is, the platen) in the horizontal
direction of the drawing.
Fifth Exemplary Embodiment
[0117] Next, an image forming apparatus according to a fifth
exemplary embodiment will be described.
[0118] The image forming apparatus according to the fifth exemplary
embodiment is different from the image forming apparatus 10
according to the first exemplary embodiment shown in FIG. 1 in that
chart image data, which is different from the chart image data
stored in the chart image memory 65 of the image forming apparatus
10 according to the first exemplary embodiment, is stored in the
chart image memory and black image data representing a black image,
which is output onto the black sheet of paper for providing a black
background to the large-size sheet of paper 404, is stored in the
chart image memory. Except the point described above, the
configuration and the operation of the image forming apparatus
according to the fifth exemplary embodiment are the same as those
of the image forming apparatus 10 according to the first exemplary
embodiment. Here, the chart images, which are represented by the
chart image data, in the fifth exemplary embodiment is different
from the chart images in the first exemplary embodiment shown in
FIG. 3 only in that the chart images have different alignment
images. Otherwise, the chart images are the same as the chart
images in the first exemplary embodiment shown in FIG. 3. As
described above, the chart images are different from those of the
first exemplary embodiment, but in the image forming apparatus
according to the fifth exemplary embodiment, the correction amounts
are calculated in the same order as that of the image forming
apparatus according to the first exemplary embodiment. The
following description will be given focusing on the different point
from the first exemplary embodiment, and a repeated description of
the same components as the first exemplary embodiment will be
omitted. Further, in the drawing, the components the same as those
of the first exemplary embodiment are represented by the same
reference numerals and signs.
[0119] FIG. 9 is a diagram illustrating the black images which are
output by the image forming apparatus on the basis of the black
image data stored in the chart image memory of the image forming
apparatus according to the fifth exemplary embodiment.
[0120] The black images shown in the drawing are constituted of an
image, which is solid black except for a peripheral margin portion,
on a front surface 4051A and an image, which is solid black except
for a peripheral margin portion and a white target image 811E, on a
back surface 4051B, and are images which are output onto both
surfaces of the sheet of paper with a predetermined size when an
instruction to output the chart images is issued by a user (that
is, when the chart image output field 2701a of FIG. 3 is touched by
a user's finger). In the fifth exemplary embodiment, the chart
images are read by using a black sheet of paper 405a having the
black images.
[0121] FIGS. 10A and 10B are diagrams illustrating a situation in
which a sheet of paper 405 is aligned on the transparent glass 250
when the large-size sheet of paper 405 having the chart images is
read in the fifth exemplary embodiment.
[0122] FIGS. 10A and 10B show an exemplary case where the upper
side part of the front surface is placed toward the transparent
glass 250 side in order to read the upper side part of the front
surface of the large-size sheet of paper 405. In this case, as
shown in FIG. 10A, a back surface 505B of the large-size sheet of
paper 405 is visible from the outside. In the chart images on the
large-size sheet of paper 405 of FIG. 10A, the two alignment images
801A and 802A on the upper side of the center horizontal line 602
and the two alignment images 803A and 804A on the lower side
thereof, which are represented by the substantially triangular
marks, in the chart images on the large-size sheet of paper 400 of
FIG. 3 are replaced by alignment images 801E, 802E, 803E, and 804E.
Here, the alignment image 801E, which has a shape like a single
line extending in the horizontal direction, and the alignment image
802E, which is represented by the substantially quadrangular mark,
are provided on the upper side of the center horizontal line 602.
In addition, the alignment image 803E, which has a shape like a
single line extending in the horizontal direction, and the
alignment image 804E, which is represented by the substantially
quadrangular mark, are provided on the lower side of the center
horizontal line 602. That is, although not shown in FIGS. 10A and
10B, the same alignment images 801E, 802E, 803E, and 804E are
printed on the front surface opposite to the back surface 505B of
FIGS. 10A and 10B together with the detection images which are
formed of the six lines 601, 602, 603, 604, 605, and 606. Further,
four identification images the same as those of FIG. 3 for
identifying those with each other are printed on four parts of the
upper and lower side parts of the back surface 505B and the upper
and lower side parts of the front surface opposite thereto,
respectively. In FIG. 10A, among the images, only two
identification images 803 and 804 on the back surface 505B are
shown.
[0123] In order to read the upper side part of the front surface of
the large-size sheet of paper 405, the upper side part of the front
surface is placed on the transparent glass 250. In this case, the
alignment image 803E on the lower side of the drawing is aligned
with the lower side edge 250a of the transparent glass 250 such
that the line of the alignment image 803E on the lower side of the
drawing between the alignment images 801E and 803E having
substantially linear shapes on the back surface 505B is on the line
of the lower side edge 250a of the transparent glass 250 as shown
in FIG. 10A. Thereby, the large-size sheet of paper 405 is aligned
with the transparent glass 250 (that is, the platen) in the
vertical direction of the drawing.
[0124] Next, as shown in FIG. 10B, the black sheet of paper 405a is
placed on the upper side part of the back surface 505B of the
large-size sheet of paper 405 on the transparent glass 250.
Thereby, the upper side part is completely covered by the black
sheet of paper 405a. Here, the transparent glass 250 is formed to
be slightly sunken compared with the surface around the transparent
glass 250. Hence, there is a level difference between the edges of
the transparent glass 250 and the periphery thereof. In a case of
reading the chart images in the fifth exemplary embodiment, it is
possible to bump the black sheet of paper 405a into both of the
upper side edge 250c and the left side edge 250b of the transparent
glass 250 with the level difference, and thereby the black sheet of
paper 405a is aligned with the transparent glass 250. The alignment
image 804E, which is represented by the substantially quadrangular
mark, on the lower side of the back surface 505B of FIG. 10A is
aligned with the target image 811E of the black sheet of paper
405a, which is aligned as described above, with the lower margin
portion of the black sheet of paper 405a interposed therebetween as
shown in FIG. 10B. Thereby, the large-size sheet of paper 405 is
aligned with the transparent glass 250 (that is, the platen) in the
horizontal direction of the drawing. Here, a proportion of the
peripheral margin portion of the black sheet of paper 405a to the
entire area of the black sheet of paper 405a is extremely small. In
the above-mentioned alignment state, the periphery of the upper
side part of the front surface as a reading target, which is
opposite to the upper side part of the back surface 505B, is
covered by the black portion of the black sheet of paper 405a.
Hence, although the margin portion of the black sheet of paper 405a
is present, it is possible to avoid the effect on the edge
detection for the upper side part of the front surface.
[0125] After the sheet is placed as described above, in a similar
manner to FIG. 4C, reading is performed in a state where the sheet
is covered by the upper cover 260, and the readout data is
generated.
[0126] Next, reading is performed on the lower side part of the
front surface of the large-size sheet of paper 405 in the
above-mentioned order, and reading is further performed on each of
the upper and lower side parts of the back surface 505B. Here, in
the case of reading the lower side part of the front surface, when
the lower side part of the front surface is intended to be placed
on the transparent glass 250, the alignment images 801E and 802E on
the upper side of the back surface 505B are respectively aligned
with the lower side edge 250a of the transparent glass 250
described in FIG. 10A and the target image 811E of the black sheet
of paper 405a aligned as described in FIG. 10B. In the case of
reading the upper and lower side parts of the back surface 505B, in
a similar manner to the back surface 505B, alignment is also
performed by using the four alignment images on the front surface.
As described above, in either of the reading operations, by using
the alignment images 801E and 802E on the upper side or the
alignment images 803E and 804E on the lower side, the large-size
sheet of paper 405 is aligned with the transparent glass 250 (that
is, the platen) in the vertical and horizontal directions of the
drawing.
[0127] As described above, the readout data is generated for each
of the upper and lower side parts of the front surface and the
upper and lower side parts of the back surface 505B, and is stored
in the readout image memory 64. The subsequent flow of the
correction amount calculation is the same as that of the first
exemplary embodiment, and thus a repeated description will be
omitted.
[0128] In the fifth exemplary embodiment, in a similar manner to
the first exemplary embodiment, any readout data reliably contains
the position information of the center horizontal line 602, and the
corners of the sheet of paper are separated from the edges of the
transparent glass. As a result, when the respective upper side
parts and the respective lower side parts of the front surface and
the back surface are read, the image forming apparatus according to
the fifth exemplary embodiment is unlikely to cause a reading
failure, in which the readout data not containing data of common
portions (for example, the center horizontal line 602) is generated
and thus it is difficult to calculate the correction amounts when a
user makes an error in placing the large-size sheet of paper 405,
and a reading failure in which it is difficult to sense the edge
positions of the sheet of paper when the readout images are
analyzed.
[0129] Further, only by using the lower side edge 250a of the
transparent glass 250 and the target image 811E of the aligned
black sheet of paper 405a as targets, the sheet of paper may be
aligned, and thus it becomes easy to align the sheet of paper.
[0130] In particular, in the fifth exemplary embodiment, the
large-size sheet of paper 405 is aligned in the horizontal
direction of the drawing. Hence, it is possible to prevent the
large-size sheet of paper 405 from protruding out of the
transparent glass 250 (that is, the platen) in the horizontal
direction of the drawing.
[0131] Furthermore, in the fifth exemplary embodiment, the black
sheet of paper 405a is output on the basis of the black image data
which is stored in the chart image memory of the image forming
apparatus according to the fifth exemplary embodiment. Hence, even
when the black sheet of paper 405a is lost or damaged, it becomes
easy to get a new black sheet of paper 405a.
Sixth Exemplary Embodiment
[0132] Next, an image forming apparatus according to a sixth
exemplary embodiment will be described.
[0133] The image forming apparatus according to the sixth exemplary
embodiment is different from the image forming apparatus 10
according to the first exemplary embodiment shown in FIG. 1 in that
chart image data, which is different from the chart image data
stored in the chart image memory 65 of the image forming apparatus
10 according to the first exemplary embodiment, is stored in the
chart image memory and the target image for aligning the chart
images is printed on the upper cover. Except the point described
above, the configuration and the operation of the image forming
apparatus according to the sixth exemplary embodiment are the same
as those of the image forming apparatus 10 according to the first
exemplary embodiment. Here, the chart images, which are represented
by the chart image data, in the sixth exemplary embodiment is
different from the chart images in the first exemplary embodiment
shown in FIG. 3 only in that the chart images have different
alignment images. Otherwise, the chart images are the same as the
chart images in the first exemplary embodiment shown in FIG. 3. As
described above, the chart images are different from those of the
first exemplary embodiment, but in the image forming apparatus
according to the sixth exemplary embodiment, the correction amounts
are calculated in the same order as that of the image forming
apparatus according to the first exemplary embodiment. The
following description will be given focusing on the different
points from the first exemplary embodiment, and a repeated
description of the same components as the first exemplary
embodiment will be omitted. Further, in the drawing, the components
the same as those of the first exemplary embodiment are represented
by the same reference numerals and signs.
[0134] FIGS. 11A to 11C are diagrams illustrating a situation in
which a sheet of paper 406 is aligned on the transparent glass 250
when the large-size sheet of paper 406 having the chart images is
read in the sixth exemplary embodiment.
[0135] FIGS. 11A to 11C show an exemplary case where the upper side
part of the front surface is placed toward the transparent glass
250 side in order to read the upper side part of the front surface
of the large-size sheet of paper 406.
[0136] In this case, as shown in FIG. 11A, a back surface 506B of
the large-size sheet of paper 406 is visible from the outside. In
the chart images on the large-size sheet of paper 406 of FIG. 11A,
the two alignment images 801A and 802A and the two alignment images
803A and 804A in the chart images on the large-size sheet of paper
400 of FIG. 3 are replaced by two alignment images 801F and 802F
and two alignment images 803F and 804F. Here, the two alignment
images 801A and 802A are respectively provided in the vicinities of
the edges of the sheet of paper 400 on the upper side of the center
horizontal line 602, and the two alignment images 803A and 804A are
respectively provided in the vicinities of the edges of the sheet
of paper 400 on the lower side of the center horizontal line 602,
but the two alignment images 801F and 802F are respectively
provided at positions close to the vertical line 605 on the upper
side of the center horizontal line 602, and the two alignment
images 803F and 804F are respectively provided at positions close
to the vertical line 605 on the lower side of the center horizontal
line 602. That is, although not shown in FIG. 11A, the same
alignment images 801F, 802F, 803F, and 804F are printed on the
front surface opposite to the back surface 506B of FIG. 11A
together with the detection images which are formed of the six
lines 601, 602, 603, 604, 605, and 606. Further, four
identification images the same as those of FIG. 3 for identifying
those with each other are printed on four parts of the upper and
lower side parts of the back surface 506B and the upper and lower
side parts of the front surface opposite thereto, respectively. In
FIG. 11A, among the images, only two identification images 803 and
804 on the back surface 506B are shown.
[0137] Next, as shown in FIG. 11B, the black sheet of paper 403a,
of which both entire surfaces are solid black, is placed on the
upper side part of the back surface 506B of the large-size sheet of
paper 406 on the transparent glass 250. Thereby, the upper side
part is completely covered by the black sheet of paper 403a. Here,
similarly to the black sheet of paper 400a shown in FIG. 4B, the
black sheet of paper 403a shown in FIG. 11B is for providing a
black background to the large-size sheet of paper 406 such that the
edge portion of the large-size sheet of paper 406 is clearly
recognized through the reading. That is, the black sheet of paper
403a covers at least a part of the space between the end portion of
the transparent glass 250 and the large-size sheet of paper
406.
[0138] Subsequently, as shown in FIG. 11C, the upper side part of
the back surface 506B of the large-size sheet of paper 406 and the
black sheet of paper 403a are covered by an upper cover 260'. Here,
two target images 2601F and 2602F are printed on the lower side
edge of the upper cover 260' shown in FIG. 11C. Thus, the two
alignment images 803F and 804F on the lower side of the back
surface 506B of FIG. 11A are aligned with two target images 2601F
and 2602F of the closed upper cover 260' as shown in FIG. 11B.
Thereby, the large-size sheet of paper 406 is aligned with the
transparent glass 250 (that is, the platen) in the vertical and
horizontal directions of the drawing. After the sheet is placed as
described above, reading is performed, and the readout data is
generated.
[0139] Next, reading is performed on the lower side part of the
front surface of the large-size sheet of paper 406 in the
above-mentioned order, and the reading is further performed on each
of the upper and lower side parts of the back surface 506B. Here,
in the case of reading the lower side part of the front surface,
when the lower side part of the front surface is intended to be
placed on the transparent glass 250, the alignment images 801F and
802F on the upper side of the back surface 506B are aligned with
the target images 2601F and 2602F of the upper cover 260' as
described in FIG. 11B. In the case of reading the upper and lower
side parts of the back surface 506B, in a similar manner to the
back surface 506B, alignment is also performed by using the four
alignment images on the front surface. As described above, in
either of the reading operations, by using the alignment images
801F and 802F on the upper side or the alignment images 803F and
804F on the lower side, the large-size sheet of paper 406 is
aligned with the transparent glass 250 (that is, the platen) in the
vertical and horizontal directions of the drawing.
[0140] As described above, the readout data is generated for each
of the upper and lower side parts of the front surface and the
upper and lower side parts of the back surface 506B, and is stored
in the readout image memory 64. The subsequent flow of the
correction amount calculation is the same as that of the first
exemplary embodiment, and thus a repeated description will be
omitted.
[0141] In the sixth exemplary embodiment, in a similar manner to
the first exemplary embodiment, any of the readout data definitely
contains the position information of the center horizontal line
602, and the corners of the sheet of paper are separated from the
edges of the transparent glass. As a result, when the respective
upper side parts and the respective lower side parts of the front
surface and the back surface are read, the image forming apparatus
according to the sixth exemplary embodiment is unlikely to cause a
reading failure, in which the readout data not containing data of
common portions (for example, the center horizontal line 602) is
generated and thus it is difficult to calculate the correction
amounts when a user makes an error in placing the large-size sheet
of paper 406, and a reading failure in which it is difficult to
sense the edge positions of the sheet of paper when the readout
images are analyzed.
[0142] Further, only by using the target images 2601F and 2602F of
the upper cover 260' as targets, the sheet of paper may be aligned,
and thus it becomes easy to align the sheet of paper.
[0143] In particular, in the sixth exemplary embodiment, the
large-size sheet of paper 406 is aligned in the horizontal
direction of the drawing. Hence, it is possible to prevent the
large-size sheet of paper 406 from protruding out of the
transparent glass 250 (that is, the platen) in the horizontal
direction of the drawing.
[0144] The foregoing description of the exemplary embodiments of
the present invention has been provided for the purposes of
illustration and description. It is not intended to be exhaustive
or to limit the invention to the precise forms disclosed.
Obviously, many modifications and variations will be apparent to
practitioners skilled in the art. The embodiments were chosen and
described in order to best explain the principles of the invention
and its practical applications, thereby enabling others skilled in
the art to understand the invention for various embodiments and
with the various modifications as are suited to the particular use
contemplated. It is intended that the scope of the invention be
defined by the following claims and their equivalents.
* * * * *